RHSA-2026:89758 - Security Advisory

Topic

An update for firefox is now available for Red Hat Enterprise Linux 10.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

Security Fix(es):

• libexpat: denial of service via crafted XML input (CVE-2026-45186)
• expat: expat: Information disclosure via heap buffer over-read in XML_ParseBuffer (CVE-2026-77214)
• firefox: thunderbird: Privilege escalation in the Application Update component (CVE-2026-109704)
• firefox: Use-after-free in the XML component (CVE-2026-109718)
• firefox: Incorrect boundary conditions in the JavaScript Engine component (CVE-2026-109715)
• firefox: firefox: Sandbox escape via incorrect boundary conditions in Win32 widget (CVE-2026-109740)
• firefox: Use-after-free in the Storage: IndexedDB component (CVE-2026-109706)
• firefox: Use-after-free in the Crash Reporting component (CVE-2026-109713)
• firefox: Use-after-free in the DOM: Core & HTML component (CVE-2026-109724)
• firefox: Information disclosure, privilege escalation in the Security: Process Sandboxing component (CVE-2026-109709)
• firefox: Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component (CVE-2026-109705)
• firefox: Use-after-free in the JavaScript Engine: JIT component (CVE-2026-109729)
• firefox: Incorrect boundary conditions in the JavaScript Engine component (CVE-2026-109716)
• firefox: Race condition, use-after-free in the Graphics: CanvasWebGL component (CVE-2026-109719)
• firefox: Integer overflow in the Layout: Text and Fonts component (CVE-2026-109723)
• firefox: Sandbox escape due to incorrect boundary conditions in the Networking component (CVE-2026-109708)
• firefox: Use-after-free in the DOM: Bindings (WebIDL) component (CVE-2026-109717)
• firefox: Sandbox escape due to use-after-free in the Networking component (CVE-2026-109707)
• firefox: JIT miscompilation in the JavaScript: WebAssembly component (CVE-2026-109720)
• firefox: Use-after-free in the SVG component (CVE-2026-109726)
• firefox: Integer overflow in the Graphics component (CVE-2026-109730)
• firefox: Use-after-free in the Audio/Video component (CVE-2026-109727)
• firefox: Use-after-free in the DOM: Streams component (CVE-2026-109732)
• firefox: Use-after-free in the DOM: Core & HTML component (CVE-2026-109725)
• firefox: Sandbox escape due to uninitialized memory in the Graphics component (CVE-2026-109712)
• firefox: Use-after-free in the Graphics: Canvas2D component (CVE-2026-109711)
• firefox: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-109722)
• firefox: Use-after-free in the DOM: Animation component (CVE-2026-109728)
• firefox: Incorrect boundary conditions in the JavaScript Engine: JIT component (CVE-2026-109721)

Bug Fix(es) and Enhancement(s):

• Firefox ESR 153 rebase [rhel-10.2.z] (JIRA:RHEL-175166)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 10 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le
• Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x

Fixes

• BZ - 2468575 - CVE-2026-45186 libexpat: denial of service via crafted XML input
• BZ - 2547476 - CVE-2026-77214 expat: expat: Information disclosure via heap buffer over-read in XML_ParseBuffer
• BZ - 2550397 - CVE-2026-109704 firefox: thunderbird: Privilege escalation in the Application Update component
• BZ - 2550404 - CVE-2026-109740 firefox: firefox: Sandbox escape via incorrect boundary conditions in Win32 widget
• BZ - 2550405 - CVE-2026-109706 firefox: Use-after-free in the Storage: IndexedDB component
• BZ - 2550413 - CVE-2026-109705 firefox: Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component
• BZ - 2550420 - CVE-2026-109729 firefox: Use-after-free in the JavaScript Engine: JIT component
• BZ - 2550424 - CVE-2026-109719 firefox: Race condition, use-after-free in the Graphics: CanvasWebGL component
• BZ - 2550433 - CVE-2026-109717 firefox: Use-after-free in the DOM: Bindings (WebIDL) component
• BZ - 2550438 - CVE-2026-109707 firefox: Sandbox escape due to use-after-free in the Networking component
• BZ - 2550446 - CVE-2026-109726 firefox: Use-after-free in the SVG component
• BZ - 2550451 - CVE-2026-109727 firefox: Use-after-free in the Audio/Video component
• BZ - 2550455 - CVE-2026-109732 firefox: Use-after-free in the DOM: Streams component

CVEs

• CVE-2026-45186
• CVE-2026-77214
• CVE-2026-109704
• CVE-2026-109705
• CVE-2026-109706
• CVE-2026-109707
• CVE-2026-109708
• CVE-2026-109709
• CVE-2026-109711
• CVE-2026-109712
• CVE-2026-109713
• CVE-2026-109715
• CVE-2026-109716
• CVE-2026-109717
• CVE-2026-109718
• CVE-2026-109719
• CVE-2026-109720
• CVE-2026-109721
• CVE-2026-109722
• CVE-2026-109723
• CVE-2026-109724
• CVE-2026-109725
• CVE-2026-109726
• CVE-2026-109727
• CVE-2026-109728
• CVE-2026-109729
• CVE-2026-109730
• CVE-2026-109732
• CVE-2026-109740

References

• https://access.redhat.com/security/updates/classification/#important